The devices for shredding paper documents for information security purpose are known as paper shredders, and are widely used for the disposal of paper documents containing sensitive information.
A paper shredder ensures the security of information by shredding paper documents finely enough for the information contained in the paper documents to be illegible, and recovery and reconstruction of information from shredded paper documents are practically impossible.
In the light of this possible inconvenience, it has been proposed to read the information in the paper documents with an image scanner or the like before they are shredded or otherwise destroyed so that the information read out from the paper documents may be retrieved when required.
Such a device is desired to be equipped with paper feed means for feeding each sheet of paper from a stack of paper placed on a paper feed table for efficient handling of a large number of paper sheets.
Some of the paper documents may not contain any sensitive material and the information contained in such paper documents may not be required to be retained in storage means. Therefore, it is preferable to shred such documents by a number of sheets at a time instead of processing the documents sheet by sheet according to the capability of the paper shredder from the view point of the efficiency of the device operation.